The guard-house originally served as the non-commissioned officers’ and men’s quarters, as well as the prison. The long walls consist of half-timbering. This is a building technique that was limited in fifteenth and sixteenth-century Norway to locations commissioned by the Danish central powers. The earliest and most important example was the town of Christiania, but it is also to be found at military sites such as the fortress town of Fredrikstad and at the shipyard at Fredriksvern. The guard-house originally served as the non-commissioned officers’ and men’s quarters, as well as the prison. The long walls consist of half-timbering. This is a building technique that was limited in fifteenth and sixteenth-century Norway to locations commissioned by the Danish central powers. The earliest and most important example was the town of Christiania, but it is also to be found at military sites such as the fortress town of Fredrikstad and at the shipyard at Fredriksvern. The guard-house is the northernmost building to have this building technique, though here in combination with a turfed roof, which gives it a local appearance. The roof is built up as a combined ridge/rafter roof with double roof boards, of which the lower ones were originally visible. The gable roof, which is covered in turf and birchbark, has five small dormer windows distributed across two western and two eastern roof surfaces.